Concur... if merely water spots (water soluble) per OP, breathing on glass followed by CLEAN cloth/wipe will handle it.
The thought of using acetone makes me cringe...when there are so many less aggressive options, including Zeiss wipes mentioned, and several cleaning solutions designed for optics when oil is involved. (fingerprints, etc.)
Acetone dissolves some plastics, paint, nail polish, and superglue.... you won't find it anywhere near my optics.